As the electoral commission members rushed to set up the ballot box and voting booth in the deerskin tent, the lashing rotors of the helicopter outside reminded them that time was ticking.

"Are we re-electing Putin?" a reindeer herder asked as he lifted the flap and came in, bundled up in hides against the -28C cold.

The three Nenets families at this windswept camp near the Arctic Circle in Siberia belong to one of the few nomadic peoples left in the world, travelling hundreds of miles in an annual migration to provide their reindeer with fresh pasture.

Almost 100km from the nearest city, the electoral commission essentially recreated a polling station in their tent before next Sunday's presidential election, in which Vladimir Putin is expected to win a fourth term in a landslide.

Within minutes, the ballots were cast, and the voting party began fighting its way back to the Mi-8 helicopter through knee-deep snow and the downwash from the rotors.

In the last presidential election, 323,200 people voted early across the many remote corners of Russia, from the Caucasus Mountains in the south to islands in the far north. Many of these ballots were cast at five-minute polling stations flown in on a helicopter, like this one.

Local electoral officials said the expensive flights merely facilitate citizens' right to vote across this vast region which juts out into the Arctic Ocean. The name Yamal means "end of the world" in the Nenets language.

"If a flight is planned, we fly. In rain, in snow, we fly because people are waiting for us," said Lyubov Markina, a polling station chairman. But this kind of voting, in small groups under the gaze of electoral officials and the police officer who flies with them, also helps pad the national leader's results.

In the 2012 elections, turnout in the Yamal-Nenets region was an astonishing 92pc, with 85pc of votes going to Mr Putin, well above the 64pc he won nationwide.

With surveys predicting a lower turnout this year, the ruling United Russia party has been especially desperate to get out the vote nationwide.

According to Nikolay Petrov, a professor at the Higher School of Economics in Moscow, the authorities are "gathering literally every vote" while trying to avoid obvious falsifications like those that led to street protests in 2011-12.

"In part the Kremlin and more so the regional elites are interested in results that look good for them, and the regions of the far north give them that possibility.

"People are for the regime there," he said.

Gennady Stepanovich (48), a nomad who will soon start the spring migration 200km north to the Gulf of Ob with 100-plus reindeer, admitted that "wages could be a little higher", but the choice was still easy.

"I'm voting for Putin. He brought up all of Russia," he said.

Aerial early voting has gone on since Soviet times in places like Nadym, a town of 45,000 that began as a small Soviet collective reindeer farm before gaining a second life when one of the country's largest gas fields was discovered nearby in 1967.

Today the region has become the homeland of the Russian gas industry, with 70pc of the country's known reserves.

In December, Mr Putin opened the Yamal liquefied natural gas plant, whose first shipment was delivered to the UK.

Of the 9,500 people who are expected to vote early in the Nadym district, only about 380 of them are reindeer herders. The rest are mostly fishermen or workers on far-flung oil and gas installations.

Electoral commission members in Nadym, one of 13 districts in the region, will fly more than 20 hours by helicopter so a few hundred isolated voters can cast their ballots early at a total cost of more than €40,500, Andrei Yurlov, head of the Nadym district electoral commission, said.

According to a 2013 Carnegie Centre Moscow report, the region is one of the "10 with the highest rating for a 'special culture' of elections, authoritarianism and/or falsifications".

An analysis of the results of all polling stations in the Yamal-Nenets region in 2012 found the percentage of votes for Mr Putin tended to be higher in those with the largest turnout. That raised the spectre of ballot stuffing or inflated vote counts.

Polling stations in the Nadym district reported turnout as high as 100pc in 2012. Mr Yurlov denied falsifications.

A good result for the current authorities, however, is almost guaranteed even without ballot-stuffing. The Yamal-Nenets region had the highest salaries in Russia in 2017, thanks largely to state-owned oil and gas companies.

Indigenous nomads are also on the government payroll, receiving wages starting at about €45 a month to raise reindeer, Nadym officials said. They also get food, supplies and equipment including, in some cases, snowmobiles.

"Reindeer herding in Yamal is a subsidised business that survives because of transfers from the budget," said Natalia Zubarevich, a Moscow State University professor.

"All the reindeer herders will vote as needed."

On Saturday, those nomads who voted communist or nationalist seemed to be in the minority. At his camp in a sea of gleaming snow, Yura Anogurichi (54) complained that the pensions he and his wife receive were "absolutely tiny".

He said he knew all the candidates from the generator-powered satellite television rigged up in his tent, but only one would do.